my jvc cdmd switches off 5 secs after switching on(ca ux-a70mdr)?

my jvc minidisc,cd player and tuner microsystem keeps on switching off about 5 seconds after switching on it will remain on standby for as long as i like and the demo runs and it all lightes up until i touch any button that switches it on,it goes on thn 5 secs then off.i am electronicly competent and have performed many fault finding procedures but is only pi*sing me off to a extreme extent .this unit has a md recorder at the bottom and a cd player at the top a swivel front disguises both players swiveling up to reviel the cd and down to reviel the md player tuner built in (very small system 4 resourses)
model no.ca ux-a70mdr
i have searched the net 4 this particular model but found nothing